View source for SN 1572

{{Short description|Supernova in the constellation Cassiopeia}}
{{Use mdy dates|date=January 2024}}
{{Infobox supernova
| name = SN 1572
| image = Tycho-supernova-xray.jpg
| image_size = 300px
| caption = [[Supernova remnant|Remnant]] of SN 1572 as seen in [[X-ray]] light from the [[Chandra X-ray Observatory]]
| epoch = ?
| type = [[Supernova#Type I|Type Ia]]<ref name="Krause2008"/>
| SNRtype = [[Nebula]]
| host = [[Milky Way]]
| constellation = [[Cassiopeia (constellation)|Cassiopeia]]
| ra = 0<sup>h</sup> 25.3<sup>m</sup>
| dec = +64° 09{{prime}}
| gal = G.120.1+1.4
| discovery = November 1572
| iauc = 
| mag_v = −4
| b-v = ~1
| distance = between {{cvt|8000|ly|kpc|lk=on}} and {{cvt|9800|ly|kpc|0}}
| progenitor = Unknown
| progenitor_type = Unknown
| notes = 
| predecessor = [[SN 1181]]
| successor = [[SN 1604]]
}}
'''SN 1572''' (''[[Tycho Brahe|Tycho]]'s Star'', ''Tycho's Nova'', ''Tycho's Supernova''), or '''B Cassiopeiae''' (B Cas), was a [[supernova]] of [[Type Ia supernova|Type Ia]] in the [[constellation]] [[Cassiopeia (constellation)|Cassiopeia]], one of eight supernovae visible to the naked eye in historical records. It appeared in early November 1572 and was independently discovered by many individuals.

Its [[supernova remnant]] has been observed optically but was first detected at radio wavelengths. It is often known as '''3C 10''', a radio-source designation, although increasingly as '''Tycho's supernova remnant'''.

==Historic description==
[[Image:Tycho Cas SN1572.jpg|thumb|left|A star map of the constellation [[Cassiopeia (constellation)|Cassiopeia]] showing the position (labelled I) of the supernova of 1572. From [[Tycho Brahe]]'s ''[[De nova stella]]'']]
The appearance of the [[Milky Way]] supernova of 1572 belongs among the most important observation events in the history of astronomy. The appearance of the "[[Nova#Historical significance|new star]]" helped to revise [[Archaeoastronomy|ancient models of the heavens]] and to speed on a revolution in astronomy that began with the realisation of the need to produce better astrometric [[star catalogue]]s, and thus the need for more precise astronomical observing instruments. It also challenged the [[Aristotelian physics|Aristotelian]] dogma of the [[Aristotelian physics#Celestial spheres|unchangeability of the realm of stars]].<ref name=":0">{{cite book|last1=Sagan|first1=Carl|url=https://books.google.com/books?id=LhkoowKFaTsC|title=Comet|last2=Druyan|first2=Ann|publisher=Random House|year=1997|isbn=978-0-3078-0105-0|location=New York|page=33|author-link1=Carl Sagan|author-link2=Ann Druyan|name-list-style=amp}}</ref>

The supernova of 1572 is often called "Tycho's supernova", because of [[Tycho Brahe]]'s extensive work ''De nova et nullius aevi memoria prius visa stella'' ("Concerning the Star, new and never before seen in the life or memory of anyone", published in 1573 with reprints overseen by [[Johannes Kepler]] in 1602 and 1610), a work containing both Brahe's own observations and the analysis of sightings from many other observers. Comparisons between Brahe's observations and those of Spanish scientist [[Jerónimo Muñoz]]<ref>{{cite journal |last=Muñoz |first=Jerónimo |date=1573 |title=Libro del nuevo Cometa, y del lugar donde se hazen; y como se vera por las Parallaxes quan lexos estan de tierra; y del Prognostico deste |url=https://gredos.usal.es/handle/10366/83106 |journal=Bg/36967(1) |location=Valencia}}</ref> revealed that the object was more distant than the [[Moon]].<ref>{{Cite web |date=4 December 2008 |title=Blast From The Past: Astronomers Resurrect 16th-Century Supernova |url=https://www.sciencedaily.com/releases/2008/12/081203133809.htm |access-date=2024-01-06 |website=[[ScienceDaily]] |language=en}}</ref> This led Brahe to approach the [[Great Comet of 1577]] as an astronomical body as well.<ref name=":0"/> Other Europeans to sight the supernova included Wolfgang Schuler, [[Christopher Clavius]], [[Thomas Digges]], [[John Dee (mathematician)|John Dee]], [[Francesco Maurolico]], [[Tadeáš Hájek]] and {{Ill|Bartholomäus Reisacher|de}}.<ref>''[https://phaidra.univie.ac.at/o:19903 De mirabili Novae ac splendidis stellae, Mense Nouembri anni 1572, primum conspectæ, ac etiam nunc apparentis, Phœnomeno]''</ref>

In England, [[Elizabeth I|Queen Elizabeth]] had the mathematician and astrologer [[Thomas Allen (mathematician)|Thomas Allen]] come and visit "to have his advice about the new star that appeared in [[Cygnus (constellation)|the Swan]] or [[Cassiopeia (constellation)|Cassiopeia]] ... to which he gave his judgement very learnedly", as the [[antiquary]] [[John Aubrey]] recorded in his memoranda a century later.<ref>{{Cite book|last=Aubrey|first=John|url=https://books.google.com/books?id=QmmGOqOXXO4C&pg=PA28|title=Aubrey's Brief Lives, Vol. 1|publisher=Clarendon|year=1898|editor-last=Clark|editor-first=Andrew|location=Oxford|page=28|language=en}}</ref>

In [[Ming dynasty]] China, the star became an issue between [[Zhang Juzheng]] and the young [[Wanli Emperor]]: in accordance with the cosmological tradition, the emperor was warned to consider his misbehavior, since the new star was interpreted as an evil omen.<ref>''Science and Civilization in China'', v. 3 pp. 425–426; cf. ''[[1587, a Year of No Significance]]''.</ref>

The more reliable contemporary reports state that the new star itself burst forth soon after November 2, 1572 and by November 11 it was already brighter than [[Jupiter]]. Around November 16, 1572, it reached its peak brightness at about magnitude &minus;4.0, with some descriptions giving it as equal to [[Venus]] when that planet was at its brightest.<ref name="ruiz"/> Contrarily, Brahe described the supernova as "brighter than Venus".<ref name=":0"/> The supernova remained visible to the naked eye into early 1574, gradually fading until it disappeared from view.<ref name="ruiz">{{cite journal |last=Ruiz-Lapuente |first=Pilar |author-link=Pilar Ruiz-Lapuente |year=2004 |title=Tycho Brahe's Supernova: Light from Centuries Past |journal=[[The Astrophysical Journal]] |volume=612 |issue=1 |pages=357–363 |arxiv=astro-ph/0309009 |bibcode=2004ApJ...612..357R |doi=10.1086/422419 |s2cid=15830343}}</ref>

==Supernova==
[[File:Tycho Light Curve.png|thumb|upright=1.5|Light curve of Tycho's supernova, reconstructed from historical observations (via the [https://sne.space/sne/SN1572A Open Supernova Catalog])]]
The supernova was classified as type I on the basis of its historical [[light curve]] soon after type I and type II supernovae were first defined on the basis of their spectra.<ref name="baade">{{cite journal |last=Baade |first=Walter |author-link=Walter Baade |year=1945 |title=B Cassiopeiae as a Supernova of Type I |url=https://adsabs.harvard.edu/full/1945ApJ...102..309B |journal=Astrophysical Journal |volume=102 |pages=309 |bibcode=1945ApJ...102..309B |doi=10.1086/144761}}</ref> The [[X-ray]] spectrum of the remnant showed that it was almost certainly of [[Type Ia supernova|type Ia]], but its detailed classification within the type Ia class continued to be debated until the spectrum of its light at peak luminosity was measured in a [[light echo]] in 2008. This gave final confirmation that it was a normal type Ia.<ref name=Krause2008/>

The classification as a type Ia supernova of normal luminosity allows an accurate measure of the distance to SN 1572. The peak [[absolute magnitude]] can be calculated from the B-band decline rate to be {{val|-19.0|0.3}}. Given estimates of the peak [[apparent magnitude]] and the known extinction of {{val|1.86|0.2}} magnitudes, the distance is {{val|3.8|1.5|0.9}} kpc.<ref name=Krause2008/>

==Supernova remnant ==
The distance to the supernova remnant has been estimated to between 2 and 5 [[kiloparsec|kpc]] (approx. 6,500 and 16,300 [[light-years]]), with recent studies suggesting a narrower range of 2.5 and 3 kpc (approximately 8,000 and 9,800 light-years).<ref>
{{cite journal |last=Tian |first=Wenwu |last2=Leahy |first2=Denis A. |date=December 26, 2010 |title=Tycho SN 1572: A Naked Ia Supernova Remnant without Associated Ambient Molecular Cloud |journal=Astrophysical Journal Letters |volume=729 |issue=2 |page=L15 |arxiv=1012.5673 |bibcode=2011ApJ...729L..15T |doi=10.1088/2041-8205/729/2/L15 |s2cid=119104584}}</ref> Tycho's SNR has a roughly spherical morphology and spreads over an angular diameter of about 8 arcminutes. Its physical size corresponds to radius of the order of a few parsecs. Its measured expansion rate is about 11–12%/year in radio and X-ray. The average forward shock speed is between 4,000 and 5,000&nbsp;km/s, dropping to lower speed when encountering local interstellar clouds.<ref>{{Citation |last=Decourchelle |first=Anne |title=Supernova of 1572, Tycho's Supernova |date=2017 |url=https://doi.org/10.1007/978-3-319-21846-5_48 |work=Handbook of Supernovae |pages=117–137 |editor-last=Alsabti |editor-first=Athem W. |access-date=2023-03-10 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-21846-5_48 |bibcode=2017hsn..book..117D |isbn=978-3-319-21846-5 |editor2-last=Murdin |editor2-first=Paul|url-access=subscription }}</ref> An older source says that the gas shell has reached an apparent diameter of 3.7 arcminutes.<ref>{{Cite web |title=SN 1572, Tycho's Supernova |url=https://spider.seds.org/spider/Vars/sn1572.html#:~:text=The%20gas%20shell%20is%20now,of%20objects%20of%20the%20two. |access-date=2023-03-10 |website=spider.seds.org}}</ref>

===Initial radio detection===
The search for a supernova remnant was futile until 1952, when [[Robert Hanbury Brown]] and [[Cyril Hazard]] reported a radio detection at 158.5&nbsp;MHz, obtained at the [[Jodrell Bank Observatory]].<ref>{{cite journal |last1=Hanbury Brown |first1=R. |author1-link=Robert Hanbury Brown |last2=Hazard |first2=C. |author2-link=Cyril Hazard |date=1952 |title=Radio-Frequency Radiation from Tycho Brahe's Supernova (A.D. 1572) |journal=Nature |volume=170 |issue=4322 |pages=364–365 |bibcode=1952Natur.170..364H |doi=10.1038/170364a0 |s2cid=4161519}}</ref> This was confirmed, and its position more accurately measured in 1957 by Baldwin and Edge using the Cambridge Radio Telescope working at a wavelength of {{val|1.9|u=m}}.<ref>{{cite journal |last=Baldwin |first=J. E. |last2=Edge |first2=D. O. |date=1957 |title=Radio emission from the remnants of the supernovae of 1572 and 1604 |url=https://articles.adsabs.harvard.edu/pdf/1957Obs....77..139B |journal=The Observatory |volume=77 |pages=139–143 |bibcode=1957Obs....77..139B}}</ref> The remnant was also identified tentatively in the [[second Cambridge Catalogue of Radio Sources]] as object "2C 34", and more firmly as "3C 10" in the [[Third Cambridge Catalogue of Radio Sources|third Cambridge list]].<ref>(Edge et al. 1959)</ref> 

There is no dispute that 3C 10 is the remnant of the supernova observed in 1572–1573. Following a 1964 review article by Minkowski,<ref>{{cite journal |last=Minkowski |first=R. |author-link=Rudolph Minkowski |date=September 1964 |title=Supernovae and Supernova Remnants |journal=Annual Review of Astronomy and Astrophysics |volume=2 |issue=1 |pages=247–266 |bibcode=1964ARA&A...2..247M |doi=10.1146/annurev.aa.02.090164.001335}}</ref> the designation 3C 10 appears to be that most commonly used in the literature when referring to the radio remnant of B Cas, although some authors use the tabulated galactic designation G120.7+2.1 and many authors commonly refer to it as ''Tycho's supernova remnant''. Because the radio remnant was reported before the optical supernova-remnant wisps were discovered, the designation 3C 10 is used by some to signify the remnant at all wavelengths.

[[File:Tour of Tycho's Supernova Remnant.ogv|thumb|left|Tour of Tycho's Supernova remnant]]

===X-ray observation===
An X-ray source designated Cepheus X-1 (or Cep X-1) was detected by the [[Uhuru (satellite)|Uhuru]] X-ray observatory at 4U 0022+63. Earlier catalog designations are X120+2 and XRS 00224+638. Cepheus X-1 is actually in the constellation Cassiopeia, and it is SN 1572, the Tycho [[Supernova remnant|SNR]].<ref name="Wood">{{cite journal |last=Wood |first=KS |last2=Meekins |first2=JF |last3=Yentis |first3=DJ |last4=Smathers |first4=HW |last5=McNutt |first5=DP |last6=Bleach |first6=RD |date=December 1984 |title=The HEAO A-1 X-ray source catalog |journal=Astrophys. J. Suppl. Ser. |volume=56 |issue=12 |pages=507–649 |bibcode=1984ApJS...56..507W |doi=10.1086/190992 |doi-access=free}}</ref>

===Optical detection===
[[Image:SN 1572 Tycho's Supernova.jpg|thumb|The red circle visible in the upper left part of this [[Wide-field Infrared Survey Explorer|WISE]] infrared image is the remnant of SN 1572.]]
[[File:Timeline of Tycho's Supernova Remnant.ogv|thumb|Expansion of Tycho's Supernova Remnant from 2000 to 2015<ref>{{cite journal |first1=Brian J |last1=Williams |first2=Laura |last2=Chomiuk |first3=John W |last3=Hewitt |first4=John M |last4=Blondin |first5=Kazimierz J |last5=Borkowski |first6=Parviz |last6=Ghavamian |first7=Robert |last7=Petre |first8=Stephen P |last8=Reynolds |date=April 6, 2016 |title= An X-ray and Radio Study of the Varying Expansion Velocities in Tycho's Supernova Remnant |arxiv=1604.01779 |doi=10.3847/2041-8205/823/2/L32 |volume=823 |issue=2 |journal=The Astrophysical Journal |page=L32|pmid=32714502 |pmc=7380093 |bibcode = 2016ApJ...823L..32W |s2cid=118542192 |doi-access=free }}</ref>]]
The [[supernova remnant]] of B Cas was discovered in the 1960s by scientists with a [[Palomar Observatory|Palomar Mountain]] telescope as a very faint [[nebula]]. It was later photographed by a telescope on the international [[ROSAT]] spacecraft. The supernova has been confirmed as [[Type Ia supernova|Type Ia]],<ref name="Krause2008">{{cite journal |last=Krause |first=Oliver |display-authors=etal |date=2008 |title=Tycho Brahe's 1572 supernova as a standard type Ia as revealed by its light-echo spectrum |journal=[[Nature (journal)|Nature]] |volume=456 |issue=7222 |pages=617–619 |arxiv=0810.5106 |bibcode=2008Natur.456..617K |doi=10.1038/nature07608 |pmid=19052622 |s2cid=4409995}}</ref> in which a [[white dwarf]] star has accreted matter from a companion until it approaches the [[Chandrasekhar limit]] and explodes. This type of supernova does not typically create the spectacular [[nebula]] more typical of [[Type II supernova]]s, such as [[SN 1054]] which created the [[Crab Nebula]]. A shell of gas is still expanding from its center at about 9,000&nbsp;km/s. A recent study indicates a rate of expansion below 5,000&nbsp;km/s.<ref>{{cite journal |last1=Hayato |first=Asami |last2=Yamaguchi |first2=Hiroya |last3=Tamagawa |first3=Toru |last4=Katsuda |first4=Satoru |last5=Hwang |first5=Una |last6=Hughes |first6=John Patrick |last7=Ozawa |first7=Midori |last8=Bamba |first8=Aya |last9=Kinugasa |first9=Kenzo |date=2010 |title=Expansion Velocity of Ejecta in Tycho's Supernova Remnant Measured by Doppler Broadened X-ray Line Emission |journal=The Astrophysical Journal |volume=725 |issue=1 |pages=894–903 |arxiv=1009.6031 |bibcode=2010ApJ...725..894H |doi=10.1088/0004-637X/725/1/894 |s2cid=119102740}}</ref>

==Companion star==
In October 2004, a letter in ''[[Nature (journal)|Nature]]'' reported the discovery of a [[Star#Classification|G2 star]], similar in type to our own [[Sun]] and named [[Tycho G]].<ref>{{cite journal |last=Ruiz-Lapuente |first=Pilar |display-authors=etal |date=2004 |title=The binary progenitor of Tycho Brahe's 1572 supernova |journal=Nature |volume=431 |issue=7012 |pages=1069–1072 |doi=10.1038/nature03006 |pmid=15510140 |arxiv = astro-ph/0410673 |bibcode = 2004Natur.431.1069R |s2cid=4346227 }}</ref> It is thought to be the companion star that contributed mass to the [[white dwarf]] that ultimately resulted in the supernova. A subsequent study, published in March 2005, revealed further details about this star: Tycho G was probably a [[main-sequence star]] or subgiant before the explosion, but some of its mass was stripped away and its outer layers were shock-heated by the supernova.<ref name=kerzendorf/>

Tycho G's current velocity is perhaps the strongest evidence that it was the companion star to the white dwarf, as it is traveling at a rate of 136&nbsp;km/s, which is more than four times faster than the mean velocity of other stars in its stellar neighbourhood.
This find has been challenged in recent years. The star is relatively far away from the center and does not show rotation which might be expected of a companion star.<ref name=kerzendorf>{{cite journal|bibcode=2013ApJ...774...99K|arxiv=1210.2713|title=A High-resolution Spectroscopic Search for the Remaining Donor for Tycho's Supernova|journal=The Astrophysical Journal|volume=774|issue=2|pages=99|last1=Kerzendorf|first1=Wolfgang E.|last2=Yong|first2=David|last3=Schmidt|first3=Brian P.|last4=Simon|first4=Joshua D.|last5=Jeffery|first5=C. Simon|last6=Anderson|first6=Jay|last7=Podsiadlowski|first7=Philipp|last8=Gal-Yam|first8=Avishay|last9=Silverman|first9=Jeffrey M.|last10=Filippenko|first10=Alexei V.|last11=Nomoto|first11=Ken'Ichi|last12=Murphy|first12=Simon J.|last13=Bessell|first13=Michael S.|last14=Venn|first14=Kim A.|last15=Foley|first15=Ryan J.|year=2013|doi=10.1088/0004-637X/774/2/99|s2cid=118470111}}</ref>

In [[Gaia DR2]], the star was calculated to be {{val|6400|2000|1200|fmt=commas}} light-years away, on the lower end of SN 1572's possible range of distances, which in turn lowered the calculated velocity from 136&nbsp;km/s to only 56&nbsp;km/s.

==In literature==
In the ninth episode of [[James Joyce]]'s ''[[Ulysses (novel)|Ulysses]]'', [[Stephen Dedalus]] associates the appearance of the supernova with the youthful [[William Shakespeare]], and in the November 1998 issue of ''[[Sky & Telescope]]'', three researchers from [[Southwest Texas State University]], Don Olson and Russell Doescher of the Physics Department and Marilynn Olson of the English Department, argued that this supernova is described in Shakespeare's ''[[Hamlet]]'', specifically by Bernardo in Act I, Scene i.<ref>{{cite web |title=Researchers say star in Hamlet may be supernova of 1572 |date=8 June 2016 |url=https://www.txstate.edu/news/news_releases/news_archive/1998/09/supernova092898.html |publisher=[[Texas State University]] |accessdate=2018-02-06 |archive-url=https://web.archive.org/web/20080906170542/https://www.txstate.edu/news/news_releases/news_archive/1998/09/supernova092898.html |archive-date=6 September 2008 |url-status=dead}}</ref>

The supernova inspired the poem "[[Al Aaraaf]]" by [[Edgar Allan Poe]].<ref>{{cite book |last=Meyers |first=Jeffrey |url=https://books.google.com/books?id=26aLzU6yr6IC&pg=PA41 |title=Edgar Allan Poe: His Life and Legacy |publisher=Rowman & Littlefield |year=2000 |isbn=978-0-8154-1038-6 |pages=41–}}</ref>

The protagonist in [[Arthur C. Clarke]]'s 1955 short story "[[The Star (Clarke short story)|The Star]]" casually mentions the supernova. It is a major element in [[Frederik Pohl]]'s spoof science article, "[[The Martian Star-Gazers]]", first published in ''Galaxy Science Fiction Magazine'' in 1962.

==See also==
{{commons category|Tycho's Supernova}}
* [[List of supernova remnants]]

==References==
{{Reflist|30em}}

==External links==
{{commons category-inline|Tycho's Supernova|SN 1572}}
* [https://sne.space/sne/SN1572A/ Light curve and spectrum of Tycho's Supernova] {{Webarchive|url=https://web.archive.org/web/20181031174018/https://sne.space/sne/SN1572A/ |date=2018-10-31 }}
* {{APOD |date=17 March 2009 |title=Tycho's Supernova Remnant}}
* [http://www.solstation.com/x-objects/tycho-s.htm solstation.com: Tycho's Star]
* [http://www.ing.iac.es/PR/newsletter/news9/science7.html The Search for the Companion Star of Tycho Brahe's 1572 Supernova]
* [http://www.cnn.com/2008/LIVING/wayoflife/01/01/important.days/index.html cnn.com: Important days in history of universe]

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{{Cassiopeia (constellation)}}
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[[Category:Historical supernovae]]
[[Category:Supernova remnants]]
[[Category:1572]]
[[Category:1572 in science]]
[[Category:Tycho Brahe]]
[[Category:Cassiopeia (constellation)]]
[[Category:Articles containing video clips]]
[[Category:Astronomical objects discovered in 1572|15721104]]
[[Category:Bayer objects|Cassiopeiae, B]]
[[Category:Bright Star Catalogue objects|0092]]
[[Category:Durchmusterung objects]]
[[Category:3C objects|10]]